


Because it is Bitter

by ouroboros



Category: Shingeki no Kyojin | Attack on Titan
Genre: Aftercare, Anal Sex, Biting, Breathplay, Fingering, First Time, Friends to Lovers, Light Dom/sub, M/M, Masturbation, Misunderstandings, Oral Sex, Pining, Rough Sex, Spit As Lube
Language: English
Status: Completed
Published: 2014-02-13
Updated: 2014-02-13
Packaged: 2018-01-12 04:36:01
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 10,163
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1181987
Author URL: https://archiveofourown.org/users/ouroboros/pseuds/ouroboros
Summary: <blockquote class="userstuff">
              <p>"There were, of course, the ways of Eren that Armin was well practiced in. There was just this one new thing about Eren that was tripping him up."</p><p>Set in Survey Corps headquarters, sometime before the Female Titan arc. Featuring an Eren who goes about sex like he goes about everything else- loud, passionate, and a little bloody. Featuring an Armin who really, really wants that, and who learns how to get what he wants.</p><p>(or, Armin feelings/boners extravaganza)</p>
            </blockquote>





	Because it is Bitter

**Author's Note:**

> Thanks to Zee for the beta and Meretricula for the titling inspiration
> 
> Apologies to Jean for using him this way. Just know that he is concealing his own feelings for Eren and Armin, even from himself. He is lovely, and deserves to be there with the two of them, just not at this point in canon.

Armin Arlert was practiced in learning by observation. He grew up watching the way his mother and father looked up at the sky, over the wall. He learned, through them, to ache for what the world held just out of his reach, even after they, too, were past his grasp. That dull voice in the back of his mind that tried to tell him that he’d never see what was out there just made him want to learn even more. He spent his formative years watching, waiting, learning.

Later, when he was in training, he passed two years healing his bruises in the quiet spaces of the evening, poring over books and maps in the obnoxiously unorganized mess of what was left of a library, carving stories and battle plans into his heart. He watched as the others learned to balance in their 3D maneuver gear, calculating angles and noting reflexes until he learned how to stay upright himself, well enough to pass, anyway.

He learned it after that first battle. It was when he couldn’t move, couldn’t turn the synapses firing madly inside his head into muscular reaction, into fighting, into saving Eren. When he couldn’t make his body do anything useful. It was one fucking hell of an observation, realizing that not moving, not fucking jumping, almost cost him Eren. It wasn’t something he wanted to learn twice.

From that moment on, he pushed his mind to the limits of sharpness. He pushed his body, small and graceless as it was, to keep up. He vowed to do, to act, to trust himself to jump, even though he knew the distance was too far for his legs to manage. How else would he learn the trajectory of his own body?

He had, for the most part, held himself to it in the year since. By now, when all eyes were on him in a moment of crisis, he didn’t hesitate- his voice was resolute, his plans were solid, his hands were steady. There was one thing, though, that he hadn’t quite worked out how to handle: Eren.

There were, of course, the ways of Eren that he was well practiced in, He knew what would make Eren laugh. He knew the threads of humanity to reach for inside of Eren when he needed a reminder that not everything was teeth and blood and vengeance. He knew when to be quiet and let Eren cry, leaving an unrepentant slick of snot and tears on Armin’s shirt. He knew when to tilt his head at Mikasa, their silent language of _you take it from here_ , written in glances and nods, woven over years of both having the same goals- _Keep him alive. Keep him warm_. He knew when the fierceness in Eren’s eyes meant _I trust you_ , or _I love you_ , or _I’m sorry_ , and he never let himself forget it. There was just this one new thing about Eren (or, more accurately, about his own reaction to Eren) that was tripping him up.

Things that had always felt normal for the two of them had started to feel less so over the past year. Armin knew himself well. He was used to keeping tabs on his own reactions, so he forced himself to take note. The first time he felt a jolt of electricity slide up his spine as Eren casually threw his arm over Armin’s shoulders, he assumed they were unrelated points of data. When it happened again, Eren playfully hooking a thumb under the 3DMG strap on Armin’s chest and snapping it, it was a coincidence. By the time the static tendrils of something were unfurling themselves from his belly button downward every time Eren grabbed his hand to pull him toward some suspicious shake of leaves, every time Eren buried his head in Armin’s neck after a particularly upsetting nightmare, it was a god damned solid unavoidable pattern.

He thought about it as he lay in bed, awake way too late again even after a gruelling day of drills (there was only just so much downtime at Survey Corps Headquarters). It wasn’t long until his hands quietly began sneaking themselves under his waistband. Jean was sleeping fitfully in the bunk above him, so he tried to choke his groans down and keep his breathing even.

He tried not to think too hard about what he was doing as his fingers slid down to wrap around his erection, but a flash of a memory from six months earlier slipped through his mental barrier. Six months ago, back when he still tried to control himself. He thought about what it had been like at first, those moments of casual contact with Eren’s skin sending sweetly painful jolts between his thighs. He wasn’t an idiot and he wasn’t a child. He knew more than enough about sex, and wasn’t like masturbation was anything new to him. It just had never been anyone specific he’d thought of before. It just had never been _Eren_. He remembered now, how, for the first few weeks after he realized how head over fucking heels he was for Eren, he had kept his hands at resolute fists at his side at night, straining to rule his body with his mind. He could almost still feel the sting of his fingernails cutting small half moons into his palms as he squeezed. He had known, even then, that he wouldn’t be able to keep it up for long. There was too much he ached to know.

That was the whole problem, really. He argued with himself about it as he let his legs fall slightly more open to reach a finger (far beyond trying to keep his hands away from himself by now) past his cock and against his perineum. He ached to know everything about Eren, and some things you just can’t learn from watching. He knew everything there was to know about the dark, lush lashes that edged Eren’s eyes from looking at them (small stolen glances at times, unabashedly staring at others), but he didn’t know what it was like to wipe tears from them with the pad of his thumb. He knew the sharp downward tug of Eren’s lips when he was worried, and the tremble that delicately took them over preceding the rush of vitriolic promise of righteous murder. He knew those lips looked soft, both in sleep and in pained scream, but he hadn’t tested the theory, hadn’t made it his. He could extrapolate data from what his hands felt, held in the rough, comfortable warmth of Eren’s hands. He couldn’t say for sure, though, what it would be like to run the back of his hand against Eren’s cheek, to tuck a finger under the straps on Eren’s thigh, to dig his fingernails into the grooves in Eren’s spine, to pull Eren down on top of him by the back of his neck, to slide his hand, damp and nervous, inside the undone front of Eren’s pants, pushing them down to his ankles, curling his fingers around Eren’s-, guiding it toward- feeling Eren push inside his-

It was dangerous to even form these thoughts into complete sentences, but he had run out of reasons to try and stop himself. So there he lay, his face buried in the blankets to muffle the small sounds he couldn’t help making. His hands were shaking, one pumping his cock, the other fingering the inside of him, his own hands pulling him closer toward the edge of orgasm. And through all of this, he thought of Eren. Eren, wild-eyed and needy above him. Eren, roughly pinning Armin’s hands above his head. Eren, pulling his hair and digging his teeth into Armin’s throat as their bodies slid rhythmically against each other. It was fucking unfair, he thought as he came, shuddering and sweat-slick, into his hand, that the knowledge of what it would feel like to have Eren inside him was inaccessible.

The urge to _touch_ to _taste_ to have every inch of him be taken by Eren’s hands and learn by doing, by feeling, by _fucking_ , was overwhelming. The very idea kept catching itself in Armin’s throat unasked for, at unexpected moments in his day, leaving him feeling dizzy, unworthy, uncomfortably hard. He imagined it would feel like heat and anger (not at each other, but at everything else) and love all at once, and he needed it the way he needed everything he’d ever wanted to learn.

He knew, just as he had learned by observation that survival necessitates a level head, that this want wasn’t something that could be easily shared. That concept was constantly battling with the promise he had made to himself to act, the promise he made the day he almost lost Eren to that stupid bearded asshole titan. There were hundreds of times he almost told him, or almost kissed him, or almost did _something_. He had thought about telling Mikasa, too, but the way she smiled softly at him whenever he leaned too hard into Eren’s embrace, the way she would squeeze his arm like an apology when Eren would pull away- it made him certain she already knew. He couldn’t bear the confirmation that he knew could come if he asked her how Eren felt about him. Because what if he didn’t feel the same, and what if she knew it? He hated his own cowardice, but he hated the thought of losing Eren as a friend even more. He knew he would have to do it eventually, though. In his mind, he was just waiting. Waiting for the right moment to jump.

And so, the flush of shame on his chest hidden by the darkness, he set to cleaning himself up. It wasn’t the best job, but getting up would make it clear to anyone still left awake that that particular round of quiet grunting was his. If he stayed in bed, he could at least pretend that he still had anonymity in a dorm full of teenagers. Above him, Jean’s mattress creaked as he turned in his sleep. Armin stared up at the frame, his body tensed at the idea that Jean might have heard. When he was sure Jean was asleep, he pulled the blanket up under his chin and forced his eyes to close. He thought of Eren, sleeping (Armin hoped he was sleeping- he knew how hard to come by sleep was for him) by himself in his room in the basement, and he mentally renewed his promise to tell him. Soon.

It didn’t occur to him until later, though, just how successful he had been at hiding it from everyone.  
______________________

it was a few days after, at the dinner table, which was a place he had previously assumed was a sacred space of sorts. It was where plans were made and stories were told and stale bread was shared, everyone continuing to gather around it even as fewer and fewer seats were taken. He felt at ease as he ate next to his friends, their elbows all bumping into each other as they leaned themselves into the woodgrain, tired after a day of even more training (they had to keep their bodies ready for whenever Humanity needed them to be sacrificed). The conversation lazed itself toward the lightness that seemed necessary after a day of preparing themselves for death.

It started with Jean, arching his back against his chair, stretching and groaning more loudly than he needed to.

“You’d think after all those drills I’d feel tired, but if anything I just feel more wound up than ever,” he said, reaching an arm up to pull at the strain in his neck.

Ymir nudged him, eyebrow cocked in what Armin knew was some kind of saucy angle, saying, “Not tired out yet, eh? You’ll just have to find another way to blow off steam, right?”

A knowing laugh passed around the table, the conversation taking a definite turn toward vulgar competition as Jean retorted good naturedly, not to be outdone.

“I have my ways,” he said, taking a rough bite of his bread and dramatically raking his gaze over everyone at the table.

Ymir laughed harder and said, “Oh I’m sure you do. You keep that hand of yours pretty busy, don’t you?”

This elicited a collective “Oooooooh” from the table. Armin eyed Mikasa, still in line for food, and wished she’d heard that- she’d have enjoyed it. He shifted his gaze to Eren, who was already seated. Always glad to see Jean as the butt of a joke, Eren was pointing at him, letting out a loud “HAH!”

At that, Armin looked down, keeping his eyes trained on his fork. The free and simple sound of laughter coming from Eren at a masturbation joke made his mind go immediately to dangerous places. Flashes of imagery rushed into his imagination- the strained and guttural noises he imagined Eren forcing from his own mouth with a kiss, a lick, a bite. He tried to shake it from his brain; he was in public, after all.

Being laughed at by Eren, of course, made Jean lose all interest in aiming a retort at Ymir. He and Eren were on friendly enough terms these days, but that wasn’t going to stop them from arguing. Jean crossed his arms and turned sharply toward Eren, still mid-point.

“Oh, right, like the sex you have is any better, Jaeger? Like you’re even able to stop obsessing over killing titans for long enough to get it on? God, what would that even be like? You throwing someone into a wall by their hair and biting them til they bleed? No fucking thank you.”

Armin couldn’t help himself- a small, pained noise escaped him as he pictured it- _That. That exactly_ , he thought. He quickly put his fork down and stifled the sound with a fist against his mouth. He turned it into a cough, desperate to not react in any way that would betray his deep-gut longing for Eren’s teeth on his arched and willing throat.

Eren opened his mouth to respond, a red flush high on his cheeks. Armin saw it and let himself hope. He wondered where the blush was coming from- was it embarrassment, or anger, or lust? What was it that Eren wanted, and did he- could he possibly know what it was that Armin wanted? He held his breath, heart thudding as he waited to see any hint of reciprocation for his feelings in Eren’s response, but Ymir cut Eren off before he could speak, rolling her eyes.

“Ugh, enough of you two, already. You’re making Armin here lose all ability to eat with your posturing bullshit. Don’t worry, Armin,” she said, clapping him on the shoulder in what she must have meant to be pleasant way, “You’re better off not having to worry about that kind of thing anyway. Good on you and your brain, being more dedicated to saving our asses than to groping someone else’s.”

Armin felt confused, like these words were meant for someone other than him. Then the laughter of the table rose high again and the sound of it pressed hot and dizzying against his ears. A chorus of his friends, nodding their agreement and looking at him with soft, patronizing eyes, all unaware of the slow sinking of his stomach. He waited for Eren to say something, to come to his defense, but it didn’t happen. He had been wrong. The small whispers of hope that had begun to bloom in him were dead. The room suddenly felt way too large, the table too tall, and Ymir’s voice, now steering the conversation to herself and her own prowess, faded into the background as Armin realized what had happened.

He had not expected this. He had wanted to hide his feelings for Eren, but he had been so convinced he had done a bad job of it that he had failed to consider that no one even thought him capable of having them in the first place. The easy compliance of their smiles made the bile in his guts rise. He tried to make eye contact with Eren across the table, but he was looking away, somewhere not at him.

Everything seemed to slide sickly into place in his mind. Of course they didn’t see that he was one of them, as good a job he did of hiding it. He knew it in his gut- they thought of him as sexless. Eren thought of him as-

He tried to cut his train of thought off, but his heart was racing with embarrassment and this new information, and his thoughts felt disjointed and unreal. _Of course Eren doesn’t notice you following the fucking angle of his shoulders with your stupid god damn sickly trained eyes._ He felt like throwing up, and all of a sudden finishing dinner seemed impossible. Armin stood up, coughing again, _As though some fake ailment would convince anyone of my need for absence,_ he thought bitterly, _surely I have some more fucking books to read, as uninterested as I must be in the topic at hand._ He stood to leave the table.

As he turned to go, he caught the corner of Eren’s eye, finally slanting to the familiar nervous edge he was used to. By then, though Armin had decided to be done analyzing the spreading flush in Eren’s cheeks. He was sure, now, that it was not for the same reason a red heat was spreading its way down his own neck. Instead, he made his way, tears stinging at his eyes, toward the bunks. He’d take it out on himself there.

Armin stumbled toward the dormitory, embarrassed by his display of weakness even though he knew no one was still watching. When he got to the door, he stopped, catching his breath. The last five minutes were playing on a manic loop in his head. Everyone seeing him as an undesirable child. _Eren_ seeing him as an undesirable child. Having been so unbelievably wrong was disorienting to him. Hot tears poured down his face and he felt even worse for it, like it proved what they had said was true. He ground his small palms into his eye sockets and gritted his teeth, breathing in sharply through the cracks. _Compose yourself. Now_ , he mandated. He looked down at his body, tiny and frail and shaking like a fucking leaf. Worst of all, he was still half hard, like his body was out to disgrace him further. This wasn’t him, wasn’t the person he’d worked up to being, and he knew it. He forced himself to slow his breathing to almost normal before turning the doorknob, finally deciding he was calm enough to be worthy of the respite he’d find inside.

He shut the door behind him and let himself sink into his mattress. His elbows pressed into his knees, his head was a heavy weight in his hands. His fingernails dug into his scalp, trying to jog some kind of last-ditch cognitive process in himself, waiting for things to make more sense.

He heard the door creak open and he pulled his head up from his hands, the strands of hair framing his face were wet with tears. His apology speech came to him, fully prepared, all at once.

“I’m sorry, I just need a minute, I-”

The rest of it died on his lips because it was Eren in the doorway, his hair disheveled from running his hands through it on the way, his forehead knotted angrily above his wide and nervous eyes. He just looked so _Eren_ that Armin forgot what speech even was for a moment, much less that he had one prepared for this particular instance.

“You’re upset,” Eren said, leaning against the door he had closed behind him.

Armin stared dumbly up at him, his hands falling to his lap. “No, no...I-” he started, betraying himself with a hiccup.

Eren’s face unbunched itself, now looking incredulously at Armin, who was suddenly extremely aware of his own red eyes and shaking shoulders. Eren pressed his back against the door and sprung forward, launching himself over to Armin’s bed in long strides, bridging the gap between them. His voice was brimming with anger and passion, as usual incapable of anything else.

“Don’t try and tell me you’re fine,” he spat, “I know you aren’t.”

His tone softened slightly as he looked down at Armin, whose eyes remained fixed on the floor, “I know you.”

Eren sat down, careful of his body and trying to be soft. Armin was thankful for it, since his own body was still vibrating with the aftershocks of adrenaline. He shifted to make room for Eren on the bed. He didn’t know what to say. He knew the words were there, ready in his brain, but he couldn’t make them travel down his synapses to his vocal cords.

Eren reached over to take Armin’s hands in his own, and Armin felt the tremors start rushing up his spine again, harder.

“Tell me what happened.”

The gears in Armin’s mind were on a nervous autopilot.

“A panic attack is an intense onset of anxiety and can be triggered by any number of things. The subject typically reaches a peak in symptomatic experience after ten to twenty minutes, after which-”

“Wha- The subject-,” Eren sputtered, cutting him off, “Armin, no, fuck the subject, we are talking about _you_.”

Armin shuddered, trying to settle his mind. This was _Eren_ , he told himself. Whatever his new and upsetting feelings for him were, Eren was always there for him, and that wouldn’t change. He hated feeling like this- unwound and lose and unsure of his next movement. Each breath felt like taking a step off a cliff, and the fall never felt worth it, though he kept having to do it. He wasn’t used to freewheeling, but he didn’t feel capable of anything else at the moment.

“Was it what Jean said?” Eren said, pressing onward. Armin felt Eren’s muscles tense against his own, “Or...or Ymir?”

Armin’s eyes flitted up at him and back down, but he still could not seem to connect his thoughts to speech. After a minute’s pause with no response, Eren shifted his weight, pushing his knee into Armin’s as the mattress squeaked under them, and spoke again.

“What is it you _want_ , Armin,?” Eren’s voice was a plaintive whimper, so much less than Armin was used to hearing. Eren was squeezing Armin’s hands in his own and pulling him closer.

It was fucking terrifying. Here it was, the moment he had craved. _What is it you want?_ the words echoed in his head, clanging demandingly. He tried not to laugh at the very question. Whole universes wouldn’t be enough to answer it, yet Eren’s eyes, fierce and green and _so goddamn close to his_ were requiring a response.

  
 _I want you, above me and around me and inside me and with me always_ , he thought.

What he said, though, was “I- I don’t know.”

“What. Do. You want?” Eren repeated, his teeth gritted, his voice low and shaking, his fingers pressing hard and unforgiving into the soft corners of Armin’s wrists. The taut muscles in Eren’s legs pushed up, pulling Armin with him until they were both standing, knees knocking into each other as they straightened. The sudden change in stance felt abrupt, like a punctuation mark, like he was meant to do something decisive, but his skin still felt tight and his lungs too small and everything around him, including Eren, was a spinning wheel of not feeling sure, and he needed to feel sure. That was what he was good at.

“What I want?” Armin whispered, finally finding his voice, “I think...I think,” he paused to breathe. Eren’s mouth looked warm and inviting and so fucking close to his own- only a few inches separated him from the knowledge of what Eren would taste like, but he was frozen with his need to not be a burden, not make Eren give anything more than he already had. He couldn’t say it. He wasn’t ready. He breathed in, shoulders trying and failing to straighten, “I just want to be left alone for a bit. I’ll be okay, don’t worry.”

As his mouth formed the sentences, he could feel the echo of himself shouting _NO NO NO NO_ rattling inside his skull, but his lips were rocks and his voice was slow tar and they were telling Eren to leave.

Eren recoiled at his words like they had burned him. His face, always expressive, was a parade of surprise, confusion, sadness and, for a moment, want. Armin noted each slight movement of Eren’s brow, each twitch of his lips. He knew that final look. He had seen the hazy deepness in those eyes before, the moment before they would rend flesh from bone. For that small space of time, Eren looked _hungry_. His top lip twitched upward and his eyes raked Armin, eye to navel and back up. Armin felt it reverberate deep inside himself, and all at once he was soft and vulnerable and immediately so incapable of standing. His knees dipped underneath him, and Eren reached to catch him, an arm bracing his waist. Eren’s face drew toward his for a moment as he stabilized them, but then backed away, like it hadn’t happened, like the rest of his body hadn’t wanted to pull itself closer.

“I’m so sorry,” Eren said, horror spreading across his face, “I didn’t mean- I’m- That’s fine. I can do that for you. If that’s what you need. I believe you.”

Eren’s arm still cradling Armin’s lower back, he lowered him back onto his bed, settling him gently down. Eren rose to stand, awkwardly stiff, so unlike his usual unforgivingly graceful self, and looking away, he nodded. He turned toward the door and started walking.

Armin’s mind was catching up with the rest of him, his regret finally finding its way from his brain to his muscles. He lifted his arm up and out, mute and shaking and his stomach turning with the familiarity of this moment, the sharp knowledge that this was the exact point in time he had lost Eren, again, but the door shut, and Eren was gone.

Armin wasn’t sure how much time passed after that. It was probably only a few minutes, but he wasn’t particularly aware of it. He was replaying the whole scene, except in the new staging in his mind, he had said something. He had done something.

He started to pace, to rewrite his lines and divine a different ending, one where he had ahold of himself, one where he acted. He began to see it, now, with an actual clarity that overrode the self-defeating truth he had forced onto himself before. Eren knew him. Eren trusted him. Eren loved him. Eren might, given the chance, want him. The panicked fog that had settled around him was clearing away. He had fucked up. He had let doubt cloud his mind, but it was not clouded any longer. His hands had stopped shaking. He started to feel the low thrill in his spine-the same one he felt when he was directing a battle plan. The thrum of action amidst uncertainty was beating in his heart and he felt heady with the power of it. He knew what he had to do next.

Just then the door opened and again and Armin turned sharply- maybe Eren hadn’t listened. Maybe he’d come back. Maybe-

The door slammed.

“Are you fucking stupid?” Mikasa said. Her voice was even but her eyes were angry. She was walking up to him, as deliberately as Eren had just a small while before. Armin just stared at her.

“You know, Armin, for being the smartest person I know, you can be pretty goddamn unobservant.”

The determined set in his eyes wasn’t lost on her. She knew him too well. She breathed in sharply, seeing the fierceness in his face. He stepped closer and she grabbed his shoulders, warm and knowing. He bent his head, resting it for a moment against her shoulder, only slightly higher than his own.

“I should have jumped, then, Mikasa. I should have jumped but I didn’t. I won’t make that mistake again.”

She ran a hand through his hair and they pulled away from each other at the same time.

“It’s not too late,” she said, “He’s in his quarters. Go.”

He nodded once at her, a quick and determined dip of his chin, and turned to leave the room.

_______________________

The walk down the hallway to the stairs didn’t take long. Armin felt like he was being pulled, like there was some invisible string knotted to his guts that was propelling him smoothly forward. His body felt light and movement was effortless, which wasn’t a sensation he was used to (using 3DMG just made him feel extremely like a bipedal land creature trying and not quite succeeding to fly). Now, though, he was fueled by the hot-burning fire of will in his mind.

Everyone was finished with dinner by this point, and they were starting to filter out into hallway. Right as he reached the door to the basement stairs, Ymir made a move to waylay him, crossing the hallway and holding a hand out to stop him. Armin was surprised to see that she actually looked like she was going to apologize, so he spoke before she could, shaking his head politely.

“Don’t worry about it,” he said, “You were incorrect, but I needed to hear it anyway. I’m on my way to do something about it now. Thank you, Ymir.”

Her eyes followed the angle of his body to the door and back. He could tell she didn’t quite understand what was happening, but she didn’t seem to care enough to let it show.

“Okaaay then? Glad to be of service,” she said, hiding her confusion with a smirk as she nodded her head back at the door, “Good luck.”

She winked at him and got out of his way. He ordinarily would have blushed (if this situation were anything like ordinary), but now he was too focused on moving forward. His body was finally synced up with his mind, and his mind was telling him to _go_.

He took the stairs two at a time. This was not something he had ever let himself do before, though he’d seen Eren do it many times. It was perhaps not the best idea, as the momentum of his body was more than he was prepared to balance. He held onto the railing, though, letting his weight fall forward, trusting his legs to catch him. The last few steps he took at a sort of ungainly half-balanced tumble, laughing a bit manically as he landed, feet first, on the floor.

He brushed himself off and looked up. The door to Eren’s room was on the right, just ten feet away. He eyed it as he walked over. There were bars set into the wood instead of a window, which made his gut twinge for Eren in a completely different way. He knew that Levi and Erwin trusted Eren now, but that didn’t stop them from keeping him locked up down here, his only view out between some rusted bars into a barely used hallway.

Lifting himself up on his toes, he could see a bit of what was inside- Eren was sitting on his bed, his head in his hands. He tried not to worry too much about his part in making Eren feel like this- he was ready to fix that. He had shut off the part of himself that overthought, running only on gut instinct and, if he was honest (which he tried always to be, at least with himself), a decent amount of lust.

His fingers reached out to test the doorknob. It wasn’t locked. He thought about knocking, but didn’t. The door creaked slightly as it opened, and Eren looked up in surprise.

“I’m sorry,” Armin said, his feet solidly pressed into the ground, his shoulders resolutely angled, his voice clear and sure, “I’m sorry, Eren. I lied before.”

Eren stood up straight, but he still looked a bit like a caged thing, all nervous teeth and unsure eyes.

“You asked me, before, what it was I wanted,” Armin said, striding his short pace over to the bed, over to Eren. He stopped just in front of him and looked up. The rush of certainty that had gotten him this far was still thrumming through his veins and he reached a hand out, lacing his slim fingers in Eren’s. He looked straight into Eren’s face. There was a small muscle tensing rhythmically in his jaw. His hair was unwashed and hanging loosely on his forehead, and there were beads of sweat gathering at his temples. His lips were pursed, his eyes burning anxiously into Armin’s.

Armin decided then that he had learned as much as it was possible to learn about Eren Jaeger with his eyes. So he kissed him. He kissed him with every part of himself that had waited for it, pushing into the weight of Eren, waiting for him to push back; craving it. Eren’s mouth froze against his own only for a moment before he opened it, leaning back into Armin. His hands wrapped around Armin’s wrists and pulled him quickly closer until their bodies were flush with each other. He slid his hands up to Armin’s shoulders, gripping them tightly as he kissed him back.

Armin had initiated the kiss but Eren was driving it now. A swell of love and terror fanned through Armin’s gut because it was _happening_. Eren’s eyes were closed and his fingers were digging into Armin’s shoulders. Eren’s mouth was hot, his tongue was slick, and his teeth were sharp. Sharp and, god, Armin’s lower lip was between them and he couldn’t keep in a gasp.

Eren pulled away, slowly, as though his body was magnetized, fighting the pull back to Armin’s. He dropped his arms and took a step back. Concern and want were warring on his face.

“Are you sure?” he said, his voice low, his breath already ragged.

“I’m sure,” Armin responded, “I want-,” his voice caught itself on the image: the things he had pictured Eren doing to him hundreds of times over the last half a year were now so close to possible that he felt faint. His eyelids fluttered as he tried to make himself meet Eren’s gaze as he said it. He breathed in deeply, shakily, and took back Eren’s hands from where they had been hanging at his sides. They were calloused and warm, and he placed one of them on the back of his own neck. Eren bit his lip and whimpered as Armin guided his other hand around behind himself to rest on the curve of his ass.

“I want what Jean said about you tonight,” said Armin, and Eren’s hands responded reflexively, tightening in Armin’s hair, squeezing his ass. Armin gasped again, a tiny hitched noise, and smiled, the sharp pain in his scalp rushing the pulse in his veins. Eren’s upper lip was twitching and Armin could feel his erection pressed against his hipbone, which made him bold. His next few steps started unfurling in his brain, and the thrill of planning them tingled in his gut.

“I want you, Eren. I’m sorry it took me so long to tell you,” he continued, grinding his hip against Eren’s crotch, “but I love you and I- I want you to fuck me.”

Eren was moving before Armin could finish his sentence. He growled and picked Armin up, supporting his weight with an arm under him while Armin wrapped his legs around Eren’s waist to hold on. Armin’s hair fell over Eren’s face as he looked down at him, and then they were kissing again, all tongue and teeth and lips fit to bruise. Eren walked them, blindly, around the corner of the bed and over to the wall.

The quick thud of his back against the cold stone almost knocked the wind out of Armin, and he leaned his head back against the wall to catch his breath. He looked down at Eren, still holding him up- his heavy lidded eyes were staring predatorily at the open arch of Armin’s neck. A smile tugged at his mouth, but Eren didn’t seem to notice. Armin tilted his head to the side and lifted a hand up to tuck his hair behind his ear, exposing even more of his skin.

Eren made a strangled groaning sound and launched himself at the dip where Armin’s neck met his shoulder, grinding his crotch into him and catching Armin’s wrist before he could lower it, pinning it against the wall as he bucked against him.

The feeling of Eren’s mouth, sharp and hot against his throat, was the new best thing Armin had ever felt. He tried, for a moment, to find something to compare it to, and failed. The whole thing was a brand new sensory experience, and he tried to burn the feeling of it into his mind. His knuckles were being ground into the stone, cutting his skin as Eren’s hand, entwined with his, braced the weight of the two of them. The way Armin’s legs wrapped around Eren’s waist made the metal buckle on the waistbelt of Eren’s 3D maneuver gear press painfully against his cock through his pants, and he thrust his hips forward to dig it in harder. Eren was surrounding him, devouring him, and there was nothing soft about it. It was perfect.

There seemed to not be enough of Armin’s neck for Eren to suck on, and with his hands busy holding Armin up, he pulled at Armin’s collar with his teeth for a moment before grunting angrily. As much as Armin loved this, he knew Eren couldn’t hold him up indefinitely. So he nudged Eren with his forehead, drawing his attention up to his face, and leaned down to kiss him, softer this time.

“You _do_ have a bed, Eren,” he murmured against his mouth.

Eren looked over at his bed like he was seeing it for the first time, his eyes sliding into focus.

“Oh,” he said, “Right.”

Armin draped his arms lazily around Eren’s neck as he carried him the few steps over to the bed; he was not really heavy enough to have to hold on tightly. Eren dropped him, not gently, on his mattress. Armin twisted his fingers around Eren’s chest strap and yanked toward himself, impatient for more body contact. That dazed hungry look was already back in Eren’s eyes, and he responded, splaying a hand on Armin’s chest and pushing him backward.

Armin let himself fall back, thumping into the mattress, his hair fanning itself around his head. His hands hovered above Eren’s legs as they moved to straddle him, ready to guide Eren’s body if he needed to. It wasn’t necessary, though. Eren was a barely contained force of lust and energy, and Armin was doing everything he could to encourage it.

Eren started unbuckling Armin’s 3D maneuver gear straps one at a time in a fumbling rush. The process took longer than it would have if Armin had just done it himself, but he wasn’t about to interrupt the movement of Eren’s hands on his body. He wondered for a moment if Eren would stop to talk about what was happening, but he decided he probably wouldn’t. Not that it mattered- it was Eren, being rough and clumsy in his affection as always.

Eren was yanking the straps off of him, jerking at the leather with drunken fingers, like he hadn’t undone his own a thousand times before. Finally, after a minute or two of rough unbuckling and pulling Armin’s torso from its restraints, his straps lay in loosed tangles around him, and Eren set to the rest of Armin’s clothes. Still straddling him, Eren fumbled with a button before shaking his head impatiently, seething through his teeth, “You do it.”

Armin lifted his fingers up to his shirt, buttoned (as always) to the top buttonhole, and undid the first in the row. Eren’s eyes were drilling into him and Armin went slower, watching Eren’s patience wane with each slow unlooping of fabric. Eren’s fingers were digging into his belly and he was rocking his hips into Armin’s, groaning quietly. His hands slid under Armin’s shirt, fingernails raking up his small, taut abdominal muscles, and Armin knew Eren did not have much patience left. The rest of his shirt came off in a half ripped, half unbuttoned frenzy, and Armin knew better than to make the removal of his pants take as long. He shimmied out of them in as methodical a rush as he could manage, doing the best he could with Eren still balancing on his knees over him, still fully clothed.

Armin was completely naked now, panting and staring up at Eren above him. His hands snaked up to Eren’s waistband, ready to do the same to him, but Eren grabbed his hands and wrenched them away, pushing them toward Armin’s cock.

“I want to watch you,” Eren said, his voice tangling on itself as he looked down.

Armin’s breath hitched in his throat at that request, which, with Eren’s fingers like iron around his hands, felt more like a command. He jerked his hands from Eren’s grip and brought them to his mouth. He licked the palm of his right hand (the one whose knuckles were already raw and a little bloody from being ground into the wall) once before wrapping it around himself. He noted the slow groan in Eren’s throat when he did, and the way Eren’s hips twitched as he hovered above him, trying not to grind down. Eren was staring him down, and Armin returned the eye contact as he took the middle and ring fingers of his left hand into his mouth, sucking on them a moment before pulling them slowly from his lips. The primary purpose for doing this was utilitarian- he had fingered himself often enough to know lubrication was useful. Eren’s reaction, however, was a goddamned fine secondary purpose. How his eyes widened, how his whole body tensed, how Armin could feel the pain and desire in Eren’s voice as he moaned his name.

“Armin, _fuck_.”

Armin started pumping his cock slowly as he reached his wet fingers around to his asshole and slipped them in, one after the other. He watched as Eren took off his clothes. It was not graceful, but it was quick. Eren grappled furiously with his buckles and ties, not looking away from Armin’s body. At that, everything started to feel a bit surreal to Armin. He was not used to being studied, but he understood where that need came from- that same hunger was pounding in his own throat. Eren had to roll off of Armin in order to take off his pants, but his eyes were locked onto his cock the whole time.

All Armin could think of were the parts of Eren he had never seen up close. His whole self had been aching for that knowledge, and all of a sudden there it was- this thing he had waited for.

Eren flung his pants on the floor and swung his leg back over Armin’s hips, settling back to rest his haunches on Armin’s thighs. There was a small moment when neither of them moved, when they were just looking at each other, taking stock.

Eren was finally naked. God, he was so naked, so ungainly and beautiful above Armin. There was a flush spreading down his neck and across his chest, which was rising and falling rapidly. Armin let his eyes trace their way down Eren’s chest, following the gentle indentation of his abs to his belly button. A dark ring of hair circled it softly (it looked soft, anyway, and fuck, Armin wanted to test that with his mouth, but his hands were busy with Eren’s previous request, and he wasn’t going to move them until Eren told him to), continuing down to his cock, slightly redder than the rest of Eren’s olive skin. Oh god, it was hard and bigger than Armin had anticipated (not huge, but significantly bigger than his own at least, which he knew, without particularly caring, was on the small side).

Armin whimpered then, thinking about the absurd proximity of Eren’s body to his, and the moment of silent tension was over. Eren leaned down, sliding his body against Armin’s, running his hands up Armin’s stomach and chest as he lay down on top of him.

“Armin,” Eren groaned, biting his ear, “you’re so goddamn beautiful.”

Those words felt like they could have been about anyone but him, about anything ever except his thin muscles tightly wound around frail bones and wrapped shudderingly in pale skin. But there he was, finally (fucking _finally_ ) underneath the quick heat of Eren, who was saying that about him. And he trusted Eren, so it must be true.

Eren kissed him, rough, and Armin knew it meant he was ready for them to be done analyzing each other. Eren reached underneath himself to where Armin still had his hands working on his dick and asshole. He dug his fingernails into Armin’s wrists, pulling his hands away, repositioning them to cross themselves on the mattress above Armin’s head, holding them in place.

Armin sucked in a breath, arching his hips upward. His cock rubbed against Eren’s, shooting tremors of pleasure through the rest of his body. Pleasure at the sensation, yes, but it was more at the simple idea that this was a thing that was happening to him.

Eren pushed back with his whole body. His cock dug against Armin’s stomach, his fingers tightened their hold on his wrists, and he sucked harder on Armin’s lip, and Armin kissed him back furiously.

“Armin,” breathed Eren, “Armin,” he repeated Armin’s name into his mouth, over and over, hardly pausing between kisses to speak it. Armin didn’t respond, only kissing back, feeling the pulse in his wrists thump under the pressure of Eren’s fingers and tasting his own mouth under the wet insistence of Eren’s.

Eren was still kissing him, still biting him, and while his mouth was on Armin’s mouth (and his neck and his earlobes) he kept talking.

“What you did before,” he choked out, “to your fingers. That- that helped? That is good to do before, ahhh-” he paused, the bucking of his own hips distracting him for a moment, and Armin knew what raw and red-tinted images were blooming in Eren’s brain, “-before I fuck you?”

Armin felt himself blushing, which felt a little absurd considering what it was they had done so far, but he couldn’t help it. He nodded. “Yes. That would help.”

“And it wont…” Eren stopped moving for a moment, propping himself up to look down at Armin, who could hear the concern creeping into his voice now, “I won’t hurt you?”

Armin shook his head, his eyes serious and his voice calm, “No. At least, not any more than I want you to. If it’s too much, I’ll tell you to stop, and you will.”

He watched Eren process this, his brow slowly unknitting itself, his eyes darting from point to point on Armin’s face.

“Eren, I trust you,” Armin said, lifting his head up to kiss him, slow and sweet. When he pulled away, Eren nodded.

Eren wasted no more time. His arms wrapped underneath Armin and twisted the both of them around until he was laying on his back with Armin on top of him. Armin started slinking down Eren’s body immediately, his mouth trailing a row of precise kisses down Eren’s chest, stopping to test his reaction to his teeth around a nipple (the reward was a yelp and a hand knotted in Armin’s hair, pushing downward). Armin’s feet reached the edge of the bed, so he let himself down to the floor, pulling Eren with him until he was sitting up, legs bent over the edge of the mattress and dangling. Armin settled his knees between Eren’s feet on the rug next to the bed and leaned in to nip at the skin on Eren’s stomach once more, breathing in the sweet, dark smell of the hair trailing down to his dick, and, without stopping to think about it, took it into his mouth.

As soon as his tongue touched the hot skin, Eren groaned, and _god_ he was loud. Armin wanted him to be louder, knowing and not caring that the sound would travel, so he pulled the sound out of him with his lips. His mouth was small, but he took it in the best he could. Eren tasted salty and the length of him pushed on the back of Armin’s throat, but that didn’t mean he didn’t want more of it. Armin’s thumbs dug into the place where Eren’s legs met his hips as his head bobbed, not quite being able to return the strength of the fingertip bruises he knew Eren had left on him, but still pressing the full weight of his want into him anyway.

“Armin, I’m ready,” Eren groaned, “please.”

Armin sucked once more, relishing the taste before stopping. Then he stuck his nails into Eren’s knees, clawing his legs toward himself, pulling Eren off the bed. They toppled onto the floor, Armin landing on his back with Eren tangled on top of him.

Eren snarled, pushing himself up onto his elbows and knees. Leaning down to grab a fistfull of Armin’s hair, he yanked, pulling his face up closer to his own. Armin looked back at him, panting and defiant. Eren’s eyes were wide and glazed and so fucking green, and his mouth was twisted up, sharp teeth glinting vicious in his smile.

“Turn around. Now.”

 _Fuck_ , Eren’s voice was low and sure and Armin’s scalp was stinging and he could’ve come right then, just from that, but instead Eren let go, and so Armin turned himself over onto his hands and knees and looked back over his shoulder.

Eren had his own cock in his hand, guiding it toward Armin’s asshole. He slipped two fingers of his own into his mouth, his eyes flicking fiercely into Armin’s when he did. He pulled them out and slid them into Armin’s ass, sending shockwaves straight to his dick. He felt the pressure of Eren’s dick on his asshole, felt Eren’s fingers stretch the opening slightly, testing it, and then pull out. Then Eren was pushing his cock into Armin, all the way, all at once. It wasn’t smooth and it wasn’t gentle, but it was Eren, _Eren_ , whose glance he caught just before his eyes rolled back in his head and a guttural moan forced itself from his throat. Eren was inside him and it tore at him, but it felt fucking _good_.

Eren’s hands gripped his hips tightly, steering him as he kneeled behind him on the floor. They pushed into each other, finding a rough rhythm in themselves. Armin felt the trace of Eren’s hands running up his back, fingernails first. One hand caught in his hair, the other wrapped itself around his neck. The pads of Eren’s fingers on Armin’s throat were pushing against his windpipe, letting just enough air in to keep him breathing, but keeping enough out that each throb of pulse in his jugular was a reminder of the power Eren held in his hands. He let himself go, letting Eren take control of what happened to him, surrendering himself to the hand at his throat, the dick inside him, the everpresent iron will all around.

The noises Eren was making were new to Armin. He had heard him scream before, in anger and in terror and in grief, and he knew the subtle differences to each. This one was similar, but deeper, somehow, and warmer. It was beautiful and wild and loud, and sometimes it was just an unintelligible cry, and oh God other times it was Armin’s name he was wailing as his body moved around him and inside him. There were other words, too, bright and hot and frenzied and all for Armin, so he called out in return, his voice high and sweet and full of fire.

Armin’s knees were grinding into the rough-hewn rug on the stone floor and his fingers were struggling for purchase in the weave of it as Eren thrusted into him. He felt the push and tug of Eren inside of him and it reverberated up his spine and out through his teeth. He was getting _fucked_. He thought of every part of Eren he had ever known, from the hidden tenderness of his youth to the tendrils of monstrosity that snaked themselves around the corners of Eren’s eyes when he weaponized himself for the good of mankind. That and everything in between- every part of Eren that Armin had ever loved- was surrounding him. The intensity of that notion coursed through him, and he shuddered, curled toes to shoulders, thinking about it. His elbows buckled slightly before straightening again, and his hands clenched into the rug, keeping himself stable on all fours.

Eren must have noticed, because he jerked the hand locked tight in Armin’s hair to the side so he could reach him, leaning over and pushing his mouth onto Armin’s. He bit down, kissing the best way he knew how, and groaned into him.

“This is still okay, right?”

Armin knew that the noises he was making were confirmation enough, but he appreciated the request, so he answered, “Yes, Eren, yes. It’s so okay, you’re so…” he trailed off, pushing his ass backward into the fast movement of Eren.

Satisfied with that, Eren slid back a bit. Keeping one hand taut in Armin’s hair, he let loose his grip on Armin’s throat and Armin gasped. He missed the pressure of Eren’s fingers already, but he knew where that hand was going. Eren ran it down Armin’s back and around the small, sharp angle of his hip, wrapping it around his cock. Eren pumped once, catching the beads of precome clinging to the underside of it, and, twisting his hand, spread it around the shaft. His hand gathered speed at he ran it up and down Armin’s erection. Armin whimpered and tried to lower his head to look underneath him, straining against Eren’s grasp in his hair- Eren was jacking him off, and, fuck, he needed to watch it. Eren loosed his hold on his hair, but only slightly, letting Armin bend his neck forward to look.

Through his spread legs he could see Eren’s thighs, tightly muscled and dusted with soft, goldenbrown hair, flexing and shifting as he fucked him from behind. Armin’s cock fit perfectly into Eren’s hand, and his knuckles were white with the pressure ( _God_ he was squeezing hard and fuck if it didn’t hurt in the best way). Armin was shivering, delirious with pleasure. It felt right then like Eren’s hands, Eren’s cock, Eren’s everything existed only for this, like he was there simply to wring this sensation out of Armin at every joint, in every twist of sinew and muscle, and that he himself existed for nothing else than to feel it.

He was shaking and so close to orgasm. The movement of Eren’s fist around his cock had risen to an erratic rushed staccato, and he knew Eren must be close, too.

Every ounce of lust and heat that had been building in him, knotting itself in his gut for the past six months, had risen to a swell. It all rushed out of him in waves as he came, hard, into Eren’s hand.

“ _Eren_ ,” he cried out as the tremors of release shook through him, one after the other. His arms were weak with it and could not hold him any longer, so he collapsed, prostrate, onto the floor, bringing Eren with him. Eren’s body lay flush on top of his now, and he put his hands on top of Armin’s, which were palm down on the floor. Intertwining their fingers, he curled their fists toward their bodies, holding Armin close. He thrusted a few more times and then burrowed his face in the back of Armin’s neck as he finished, burying a final scream into his hair.

They lay there for a moment, finally silent except for the sounds of their breathing, heavy and sated. Eren pulled out, rolling off of Armin and onto his side, giving Armin space to do the same. They lay there on the floor, bent knees touching and eyes searing into each other with the force of what they’d just done.

Armin brushed the hair out of Eren’s face and cupped his cheek with the palm of his hand, leaning in to kiss him. It was slow, the neediness of earlier ebbing out of them. Breaking away, Armin looked up at the bed next to them and laughed quietly to himself.

“What’s so fu-” Eren started to ask, but then he followed Armin’s eyes up to where their clothes and straps were dangling off the edge of the mattress, and he understood, “oh, right,” he said, looking around like it was the first time he’d seen his own room, “we’re on the floor.”

Armin smirked wider at that, and watched as Eren picked himself up to standing and cleared his bed of their clothes with a sweep of his hands. He reached down to where Armin was still laying, smiling bemusedly back up at him. Armin waited a moment before taking Eren’s hand, pausing to admire his body from that angle. His stance was wide, his back straight, his knees a little red from rugburn, and his dick still half hard. He looked down at Armin like this was nothing out of the ordinary, unapologetically impatient for Armin to take his outstretched hand. Armin felt his heart swell, and he reached up to comply.

When they were both standing, Eren put his hands lightly on Armin’s shoulders and kissed him, his fingertips guiding him back to the bed. Armin let himself be steered backward, led softly to sitting, and then pulled to laying on his back. Eren climbed onto the bed, straddling him. His eyes were set and even more determined than usual.

“Eren, what are you-” Armin started to say, but Eren cut him off with a kiss. He picked up Armin’s hands and then kissed each of his knuckles one at a time, the blood on them now dried. He kissed Armin’s knees, scraped redder than Eren’s were. He kissed the already blooming bruises on Armin’s neck, and the ones his thumbs had pressed into his hips. Everywhere Armin’s skin was raw, Eren’s mouth was there, slow and soft and thankful. When he had kissed every nick and scrape and blush of blue, he crawled back up Armin’s body and nestled his face into his neck.

Armin tucked a finger under Eren’s chin and lifted his face toward his own, driving the sharp blue of his gaze into Eren’s. When Armin kissed him, he bit Eren’s lip harder than he had before, to let him know it was okay.

They did not talk about the future- about titans or death or war, or even about the immediate future that would be Levi, coming down any minute to lock Eren’s door for the night. They just held each other, their bodies tangled in angular boyish warmth, and they breathed each other in.

Armin traced his thumb across Eren’s forearm where he remembered the flesh being sundered from itself. And because now he knew he could, he ran his fingernails up along Eren’s arm, across the tendons in his neck, and up into his hair. Parts of this, of him, felt familiar, and other parts were totally new. His mind was rushing with this fresh data, his fingers grazing the impossibly soft parts of Eren’s neck, up behind his ears.

He was certain this was nothing anyone had bothered to catalog before. This was a shame for every other human in existence, because the low contented hum in Eren’s throat as Armin trailed his thumbnail across his clavicle was a major fucking discovery for Humanity. The hum rose to a growl as Eren pushed his face further into Armin’s neck, the hunger already sounding in his throat. Armin turned his head, baring his neck for Eren again. They had time for it now. And when the beasts of tomorrow would come for them, they would be ready. Hand in hand, tongue in teeth, heart in terrible claw.

**Author's Note:**

> In the desert  
> I saw a creature, naked, bestial,  
> Who, squatting upon the ground,  
> Held his heart in his hands,  
> And ate of it.  
> I said, “Is it good, friend?”  
> “It is bitter—bitter,” he answered;
> 
> “But I like it  
> “Because it is bitter,  
> “And because it is my heart.”  
> -Stephen Crane


End file.
